学科分类
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5 个结果
  • 简介:Inphasefieldfracturemodelsthevalueoftheorderparameterdistinguishesbetweenbrokenandundamagedmaterial.Atcrackfacestheorderparameterinterpolatessmoothlybetweenthesetwostatesofthematerial,whichcanberegardedasphases.Thecrackevolutionfollowsimplicitlyfromthetimeintegrationofanevolutionequationoftheorderparameter,whichiscoupledtothemechanicalfieldequations.Amongotherphenomenaphasefieldfracturemodelsareabletoreproducecracknucleationininitiallysoundmaterials.Fora1Dsettingithasbeenshownthatcracknucleationistriggeredbythelossofstabilityoftheunfractured,spatiallyhomogeneoussolution,andthatthestabilitypointdependsonthesizeoftheconsideredstructure.Thisworknumericallyinvestigatestowhichextendsizeeffectsarereproducedbythe2Dphasefieldmodel.Exemplarily,afiniteelementstudyoftheholesizeeffectisperformedandthesimulationresultsarecomparedtoexperimentaldata.

  • 标签: 相场模型 规模效应 模型模拟 骨折 尺寸效应 演化方程
  • 简介:MagnesiumalloyEZ10(Mg-RE-Zn)wasdeformedintensionattemperaturesfrom20upto520°C.Arapiddecreaseoftheyieldandtensilestrengthwithtemperaturewasobservedattemperatureshigherthan300°C.Ontheotherhand,ductilityofsamplesrapidlyincreasedinthesametemperaturerange.Lightmicroscopyandscanningelectronmicroscopywasusedtorevealthereasonforthesebehaviours.Intermetallicparticlesingrainboundariesareresponsibleforexcellentmechanicalpropertiesatlowertemperatures.Diffusionalprocessesoccurringattemperatureshigherthan300°Csignificantlyinfluencedthedeformationmechanismaswellasthefracturecharacter.

  • 标签: 镁合金 抗张强度 断裂性 扫描电子显微镜 温度范围 高温
  • 简介:ThedistributedopticalfibersensingtechnologywasusedtoinvestigatethefracturebehavioroftheEpoxyAsphaltMixture.Thespatialdistributionandvariationofthestraindevelopmentwithcrackpropagationwereacquiredusingthebrillouinopticaltime-domainreflectometerthroughtheloadingexperimentsofthecompositebeamstructure.Inaddition,afiniteelementmodelofthecompositebeamstructurewasdevelopedtoanalyzethemechanicalresponsesoftheepoxyasphaltmixtureusingtheextendedfiniteelementmethod.Theexperimentalresultsshowthatthedevelopmentofcrackpropagationbecomesinstablewiththeincreaseoftheload,andlargerloadswillgeneratedeepercracks.Moreover,thenumericalresultsshowthatthemechanicalresponseofthecracktipchangeswiththecrackpropagation,andtheworstareasthatsubjectedtocrackdamagearelocatedonbothsidesofthecompositebeamstructure.

  • 标签: 分布式光纤传感技术 环氧沥青混合料 断裂行为 沥青路面 数值模拟 组合梁结构
  • 简介:在变硬降水的Fe–Ni的变丑和破裂的导致氢的修正基于奥氏体的合金借助于控告实验,张力的测试,扫描电子显微镜学(SEM)和传播电子显微镜学(TEM)的热氢在现在的学习被调查了。它被发现′粒子受到在塑料变丑期间的由脱臼的多重砍,它支持脱臼的出现平面滑倒。而且,合金将被在macroscale导致紧张本地化的形成的氢提高。那么,在合金的变丑和骨折的机制被建议了以严肃导致氢平面在能导致宏观的紧张本地化的microscale滑倒。

  • 标签: 铁镍基合金 塑性变形 沉淀硬化 奥氏体 断裂 透射电子显微镜
  • 简介:骨头接枝可以被需要用metaphyseal在老病人填满骨头缺点弄碎的远侧的半径骨折。在这回顾,nonrandomized,单个外科医生的学习,我们评估了与使矿物化的骨胶原(MC)使用两块背面的锁住板与或没有扩大的临床、放射线学的结果为老病人与的骨头接枝背面地,metaphyseal弄碎半径破裂。在组1的病人(n=12)在组2用MC骨头接枝申请与背面的锁住的盘子被对待进metaphyseal骨头缺点,和那些(n=12)仅仅与背面的锁住的盘子。临床、放射线学的参数在外科以后在三和12个月被决定。在最后的后续,没有重要差别在2个组之间被注意以手掌倾斜并且光线的倾斜(p=0.80);然而,尺骨的变化在没有扩大,2与背面的锁住的盘子对待的组显著地增加了(p<0.05)。机能上地,这些组之间没有重要差别。我们的初步的学习建议骨头接枝代用品和背面的锁住盘子可以是的MC的那联合一为有metaphyseal的老病人有用地其他弄碎的远侧的半径骨折。

  • 标签: 粉碎性骨折 骨移植 替代物 板带 桡骨 老年